Rapid development of a mobile terminal and a wearable device brings various convenience to people's life. In daily life, when leaving home, a user may forget to carry an article of the user such as a key, a mobile phone, or a wallet; or when a user takes a child or a pet to go shopping, the child or the pet gets lost; or a user may accidentally lose some valuables when the user is out for business. Therefore, searching for a lost article is an extremely common demand in daily life.
In the prior art, there is a product that performs positioning based on a global positioning system (English full name: Global Positioning System, GPS for short). Because an error exists in GPS positioning, only an approximate location of a second device can be provided roughly, which increases searching difficulty of the user. In addition, a GPS positioning function cannot be used indoors, and cannot implement high-precision positioning indoors. Moreover, there is also a wireless tag (or a wearable device such as a smart band or a smart watch) with an anti-lost/retrieving function. In general, a mobile terminal and a wireless tag (or a wearable device) are kept connected by means of a wireless connection. Besides conventional communication, an anti-lost/retrieving function is further designed. A received signal strength indicator (English full name: Received Signal Strength Indication, RSSI for short) threshold is set in the mobile terminal, and when wireless signal strength is less than the preset threshold or the wireless connection is disconnected, the mobile terminal reminds the user to search in time in a manner of ringing, vibrating, or the like. In terms of device retrieving, when the mobile terminal and the wireless tag (or the wearable device) are kept wirelessly connected, searching may be performed by means of a sound after the mobile terminal triggers the wireless tag (or the wearable device) to sound; or when the wireless signal strength is less than the preset threshold or the wireless connection is disconnected, the wireless tag (or the wearable device) may sound automatically, so that the user can search by means of a sound. However, it is difficult to quickly and accurately determine a position by means of an auditory sensation of a human ear; searching and listening need to be performed at the same time, have low efficiency, and are extremely likely to be affected by ambient noise, a time limit, or an obstruction; and the user is not likely to perceive that the wireless tag (or the wearable device) is lost.